(Source: AFP via Yahoo & Science Daily)

Image Courtesy: IOP - Energy consumption and GHG emissions per PKT (The vehicle operation components are shown with gray patterns. Other vehicle components are shown in shades of blue. Infrastructure components are shown in shades of red and orange. The fuel production component is shown in green. All components appear in the order they are shown in the legend.)

Do you worry a lot about the environment and do everything you can to reduce your carbon footprint? Are you the one who frets about  tailpipe emissions, greenhouse gases and climate change?

If yes,  you must be the one who prefers to take the train or the bus rather than a plane, and avoid using a car whenever you can, faithful to the belief that this inflicts less harm to the planet.

Well, there could be a nasty surprise in store for you, for taking public transport may not be as green as you automatically think, says a new US study published in Environmental Research Letters, a publication of Britain’s Institute of Physics.  Often unknown to the public, there are an array of hidden or displaced emissions that ramp up the simple “tailpipe” tally, which is based on how much carbon is spewed out by the fossil fuels used to make a trip. Environmental engineers Mikhail Chester and Arpad Horvath at theUniversity of California at Davis say that when these costs are included, a more complex and challenging picture emerges.

The pair give an example of how the use of oil, gas or coal to generate electricity to power trains can skew the picture.

Boston has a metro system with high energy efficiency. The trouble is, 82 percent of the energy to drive it comes from dirty fossil fuels.  By comparison, San Francisco‘s local railway is less energy-efficient than Boston’s. But it turns out to be rather greener, as only 49 percent of the electricity is derived from fossils.

The paper points out that the “tailpipe” quotient does not include emissions that come from building transport infrastructure — railways, airport terminals, roads and so on — nor the emissions that come from maintaining this infrastructure over its operational lifetime.

The researchers also touch on the effect of low passenger occupancy and show that we are naïve to automatically assume one form of transport is more environmentally friendly than another. They conclude from their calculations that a half-full Boston light railway is only as environmentally friendly, per kilometre traveled, as a midsize aircraft at 38 per cent occupancy.  From cataloguing the varied environmental costs the researchers come to some surprising conclusions. A comparison between light railways in both Boston and San Franciso show that despite Boston boasting a light railway with low operational energy use, their LRT is a far larger greenhouse gas (GHG) emitter because 82 per cent of the energy generated in Boston is fossil-fuel based, compared to only 49 per cent in San Francisco.

Total life-cycle energy inputs and GHG emissions contribute an additional 155 per cent for rail, 63 per cent for cars and buses, and 32 per cent for air systems over vehicle exhaust pipe operation.

Journal reference:

• Mikhail V Chester and Arpad Horvath. Environmental assessment of passenger transportation should include infrastructure and supply chains. Environmental Research Letters, 2009; 4 (024008) DOI: 10.1088/1748-9326/4/2/024008

One giant container ship can emit almost the same amount of cancer and asthma-causing chemicals as 50m cars, study finds

(Source: Guardian via Tree Hugger)

The Guardian has a pretty shocking piece about giant cargo ships and the pollution they emit. The title of this post is a line from “confidential data from maritime industry insiders”, and according to them, the low-grade ship bunker fuel that powers cargo ships has up to 2,000 times the sulphur content of diesel fuel used in US, and European automobiles and emission control is practically non-existent.  Here we can see that the primary concern with shipping is air-pollution (“US academic research which showed that pollution from the world’s 90,000 cargo ships leads to 60,000 deaths a year in the US alone and costs up to $330bn per year in health costs from lung and heart diseases”). It does contribute significantly to global warming, but about 5-6 times less than land-based transportation.

Shipping by numbers (From Guardian)The world’s biggest container ships have 109,000 horsepower engines which weigh 2,300 tons.

Each ship expects to operate 24hrs a day for about 280 days a year

There are 90,000 ocean-going cargo ships

Shipping is responsible for 18-30% of all the world’s nitrogen oxide (NOx) pollution and 9% of the global sulphur oxide (SOx) pollution.

One large ship can generate about 5,000 tonnes of sulphur oxide (SOx) pollution in a year

70% of all ship emissions are within 400km of land.

85% of all ship pollution is in the northern hemisphere.

Shipping is responsible for 3.5% to 4% of all climate change emissions

The calculations of ship and car pollution are based on the world’s largest 85,790KW ships’ diesel engines which operate about 280 days a year generating roughly 5,200 tonnes of SOx a year, compared with diesel and petrol cars which drive 15,000km a year and emit approximately 101gm of SO2/SoX a year.

(Source: MIT Technology Review)

The chair of the California Air Resources Board has some advice for the new administration.

In 2006, the state of California passed landmark legislation aimed at limiting green-house gas emissions. Under the Bush administration, the Environmental Protection Agency (EPA) rejected the state’s request to regulate vehicular emissions. Earlier this month, the Obama administration announced it would reconsider this ruling–most likely in order to reverse it.

Mary D. Nichols, chairman of the California Air Resources Board, will be responsible for implementing the state’s climate change legislation. In a speech at the Berkeley Energy and Resources Collaborative annual Energy Symposium yesterday, Nichols had some advice for a new presidential administration with the will to act on climate change: follow California’s lead on energy efficiency because it’s been an economic boon for the state. Nichols mentioned a report by Next 10 that claims cutting energy usage over the past 30 years has created 1.5 million jobs in California. (Still, in a state characterized by suburban sprawl, carbon dioxide emissions are quite high, at 11 tons per capita per year.)